Hoppers equipped with conveyors are used to handle diverse types of bulk materials. These materials vary in particle size from finely ground feed materials to grains as shelled corn and soybeans. The moisture content of the material usually varies so that the material can pack and bridge in the hopper. Sticky material, such as gluten, is difficult to handle in conventional hoppers. Bridging and packing of gluten in the hoppers are problems.
Feed mixing boxes equipped with augers are used to carry and mix particulate feeds. Examples of feed mixing boxes are disclosed by Heider in U.S. Pat. Nos. 3,085,789; 3,153,494; and 3,356,270. These boxes have shields and covers located in the boxes over the augers. Vertical walls are used to divide the box into two chambers. The shields and covers each have uniform width and function to regulate the flow of material from the auger located along the bottom of the box. Bridging of material in the box chambers is reduced with movable valve gates. The gates are adjustable to control the flow of material from the hopper chambers to the auger.